1. Field of the Invention
The present invention relates to a radio-paging receiver for personal use, which has a function of transmitting and receiving a message consisting of a plurality of characters as well as a function of displaying the message on a display screen.
2. Prior Art
Japanese Patent Application No. 6-77881, published in 1994, discloses a radio-paging receiver capable of changing a way of displaying message characters. According to this conventional radio-paging receiver, a message is read out from a character generator, and the total number of characters thus read out is detected by counting pulses generated upon every input of characters. Based on the total number of characters, the size of each character to be displayed is switched between 2N.multidot.2M dots and N.multidot.M dots, where N and M are integers.
Recent development in the field of the radio-paging system has significantly reduced the size and weight of each radio-paging receiver to improve the handiness. However, reducing the overall size of the radio-paging receiver will conflict with improvement of visibility of characters on the display screen.
More specifically, in accordance with an earnest desire to enlarge the length of a message transmissible or receivable, there is a tendency that the display screen is increased in its capacity or size to display at a time as many message characters as possible. To satisfy such a request, it is mandatorily necessary to provide a large display screen. This is why the recent development of the radio-paging receiver has been encountering with the above-described two conflicting subjects (i.e. the improvement of the handiness and the improvement of visibility).
According to the above-described conventional radio-paging receiver, the character size is forcibly reduced to a smaller one whenever the length of the message exceeds a predetermined value. In other words, for the purpose of increasing the number of characters to be displayed at a time on the display screen, the above-described conventional radio-paging receiver victimizes the visibility of displayed characters. For example, when the number of displayed characters is increased, the size of each character needs to be reduced. On the other hand, if the size of each character is increased, the number of characters displayable on the screen at a time will be reduced.